一个GridView，一个DropDownList，一个Button ，
DropDownList为（0，最近7天），（1，最近15天），（2，最近30天），（3，查询所有）
当button点击时，根据DropDownList的SelectedIndex值查询。
该怎么循环查询好些呢。
- C# code
protected void btn_cha_Click(object sender, EventArgs e) { if (ddl7.SelectedIndex == 0) { GridView1.DataSource = null; string sql = "select * from [jinhuo] where datediff(day,j_date,'" + DateTime.Now.ToShortDateString() + "')<7 and user_name='" + Session["userName"] + "'"; SqlConnection con = new SqlConnection(conString); con.Open(); SqlCommand cmd = new SqlCommand(sql, con); SqlDataReader sdr = cmd.ExecuteReader(); GridView1.DataSource = sdr; GridView1.DataBind(); con.Close(); sdr.Close(); } if (ddl7.SelectedIndex == 1) { GridView1.DataSource = null; string sql = "select * from [jinhuo] where datediff(day,j_date,'" + DateTime.Now.ToShortDateString() + "')<15 and user_name='" + Session["userName"] + "'"; SqlConnection con = new SqlConnection(conString); con.Open(); SqlCommand cmd = new SqlCommand(sql, con); SqlDataReader sdr = cmd.ExecuteReader(); GridView1.DataSource = sdr; GridView1.DataBind(); con.Close(); sdr.Close(); } if (ddl7.SelectedIndex == 2) { GridView1.DataSource = null; string sql = "select * from [jinhuo] where datediff(day,j_date,'" + DateTime.Now.ToShortDateString() + "')<30 and user_name='" + Session["userName"] + "'"; SqlConnection con = new SqlConnection(conString); con.Open(); SqlCommand cmd = new SqlCommand(sql, con); SqlDataReader sdr = cmd.ExecuteReader(); GridView1.DataSource = sdr; GridView1.DataBind(); con.Close(); sdr.Close(); } if (ddl7.SelectedIndex == 3) { GridView1.DataSource = null; string sql = "select * from [jinhuo] where user_name='" + Session["userName"] + "'"; SqlConnection con = new SqlConnection(conString); con.Open(); SqlCommand cmd = new SqlCommand(sql, con); SqlDataReader sdr = cmd.ExecuteReader(); GridView1.DataSource = sdr; GridView1.DataBind(); con.Close(); sdr.Close(); } }------解决方案--------------------------------------------------------
别的不说，如下
- C# code
private void ExecSql(string sql){ GridView1.DataSource = null; SqlConnection con = new SqlConnection(conString); con.Open(); SqlCommand cmd = new SqlCommand(sql, con); SqlDataReader sdr = cmd.ExecuteReader(); GridView1.DataSource = sdr; GridView1.DataBind(); con.Close(); sdr.Close();} protected void btn_cha_Click(object sender, EventArgs e) { string sql = ""; if (ddl7.SelectedIndex == 0) { sql = "select * from [jinhuo] where datediff(day,j_date,'" + DateTime.Now.ToShortDateString() + "')<7 and user_name='" + Session["userName"] + "'"; } if (ddl7.SelectedIndex == 1) { sql = "select * from [jinhuo] where datediff(day,j_date,'" + DateTime.Now.ToShortDateString() + "')<15 and user_name='" + Session["userName"] + "'"; } if (ddl7.SelectedIndex == 2) { sql = "select * from [jinhuo] where datediff(day,j_date,'" + DateTime.Now.ToShortDateString() + "')<30 and user_name='" + Session["userName"] + "'"; } if (ddl7.SelectedIndex == 3) { sql = "select * from [jinhuo] where user_name='" + Session["userName"] + "'"; } ExecSql(sql); }